1. Field of the Invention
The present invention relates to disk players for playing digital versatile disks (DVDs) and the like.
2. Description of the Related Art
Recently, DVDs for use as disk information-storage media have attracted greater attention. The DVDs have a diameter of 12 cm and a thickness of 1.2 mm. Although the DVDs have the same form as compact to disks (CDs), the single and double-sided DVDs achieve storage capacities of 4.7 gigabytes and 9.4 gigabytes, respectively, by increasing the storage density.
The DVDs store various types of data by employing an image data compression technique and an audio data compression technique based on MPEG-2. One type of stored data is control data for performing each function. For example, when a movie is stored in a DVD, it is normal to store video data and audio data in the DVD. In addition, the DVD may store a plurality of subtitle data, so that subtitles of the language selected by a user can be displayed. The DVD may also store static image data, such as profiles of a director of the movie and profiles of actors/actresses who played in the movie. The contents of these static image data are displayed according to an operation performed by the user. In addition, the DVD can store a playback start position marked (specified) by the user during playback. A DVD player can thus start to play the DVD from the marked playback start position (hereinafter referred to as a “marking function”). The DVD player plays the DVD by reading data required for performing the functions from the DVD.
The DVD player performs the marking function by storing the playback start position marked by the user during playback and associating the playback start position and a number (playback start position number). Subsequently, the DVD player plays the DVD from the playback start position associated with the playback start position number selected by the user.
It is also possible to restart the DVD from a stop position after the DVD is paused (hereinafter referred to as a “pre-stop function”). The DVD player reads various data from the DVD and performs various operations to execute the functions.
The user is required to memorize the correspondence between the marked playback start position and the playback start position number so as to enable the conventional DVD player to execute the marking function. If the user forgets the correspondence, he/she fails to properly select a desired playback start position. When numerous playback start positions are marked, the user has difficulty in memorizing the correspondence between each playback start position and each playback start position number. In this case, the user selects one of the playback start position numbers as he/she thinks appropriate, and determines whether the DVD should be played from the desired playback start position after viewing images played by the DVD player. If the determination is negative, the user selects another playback start position number. Thus, the user often fails to properly select the desired playback start position. Even if a single playback start position is marked, after a few days since the marking of the playback start position, the user often fails to remember the contents of images to be played by the DVD player when the playback start position is selected. It is inconvenient for the user to use the marking function, and the conventional marking function is disadvantageous in that the user has difficulty in memorizing the contents of data to be read in correspondence with a stored playback location.
The pre-stop function is executed by holding an optical pickup for detecting data stored in the DVD in place where the playing of the DVD is stopped. In response to an instruction to restart playing, the optical pickup is immediately restarted to play the DVD from the stop position.
When the playing is completely stopped and the power is turned off, the optical pickup returns to the original position (for example, the position from which data written to the innermost circle of the DVD is read). In this case, the user is required to give various instructions, such as playing, fast-forwarding, and rewinding, in order to find the appropriate stop position. The operation becomes burdensome, and thus the DVD player has difficulty in playing the DVD from the right stop position.